It was not only diet and exercise that got her into the best shape of her life…

Her vegan boyfriend Matthew Mosshart helped too!

She said:

"Over the past two years, I've lost over four-and-a-half stone [63 pounds] - but I've only lost the last stone since I met Matthew. That's because he cooks for me! He's a vegan chef, so he makes sure that I eat healthily."

So she lives with a chef!!

A healthy vegan chef at that! And he's a hunk! Sounds like she hit pay dirt!

She continued:

"I'm happy with how I look now. As long as I'm healthy, do exercise and eat right, that's the main thing. I'm slim now, but I don't want to be anorexic. I love Matthew and we love to work out together - we motivate one another. I go on the treadmill every day for half an hour and do two hours of exercise if I have a special event."

That's so normal!

She doesn't follow one crazy diet or some super intense diet and exercise regimen.

This isn't the first time the 39-year-old's figure has caused controversy. As we reported in January, the American Pie stunner was accused of using Photoshop to make her already narrow waist even smaller.

Reid has admitted to getting plastic surgery in the past to make changes to her abdominal area and breasts -- but the actress asserts that she naturally has a lean shape.